Correct. there was actually a period of time when trees had no predators or scavengers that could break down their body matter. They actually likely caused mass extinction events during that time.
Sources: Hank Green talking about it (just a fun video, I wouldn’t take it as gospel necessarily)
IFL Science article (I cross-referenced this with multiple other articles and it seems to talk about a cempletely different mechanism for mass extinction to occur)
Check out WEBFISHING.